/*************************************************************************
	> File Name: 3.fflush.c
	> Author: WangYiFei
	> Mail: 824537320@qq.com
	> Created Time: Thu 07 Jan 2021 10:08:29 PM CST
 ************************************************************************/

#include <stdio.h>
#include <unistd.h>

int main() {
    fprintf(stderr, "hello world");
    // printf("Hello World!");
    // fflush(stdout);
    sleep(1);
    printf("\n");
    sleep(5);


    return 0;
}
